Safety device for centrifugal machines



Nov. 1929. H. J. M. c. KRANTZ 3 SAFETY DEVICE FOR CENTRIFUGAL MACHINESFiled Oct. 25, 1926 Patented Nov. 26, 1929 HUBER! J. H. C. KRANTZ, FMCHEN, GERMANY SAFETY DEVICE FOR GENTRIFUGAL MACHINES Application "filedOctober 25, 1926. Serial No. 144,942.

This invention relates to a .centrifu 'al machine, and particularly to asafety device therefor, the same being in the nature of an improvementupoh what isshown and described in my co-pending application Serial Anobject of the present improvement is to provide a safety device whichwill operate to prevent opening movement of themachine 19 cover untilafter the rotating element of the machine has ceased to move.

A more detailed object is to provide an automatically operable latchmember suitably connected with the rotating element of the machine insuch manner that the latch will move to unlatching position only whenmovement of the rotating element of the machine has stopped, orpractically so.-

Other objects and'aims of the invention,

more or less specific than those referred to above, will be in partobvious and in part .pointed out in the'course of the followingdescription of the elements, combinations, arrangements of parts andapplications .of principles constituting the invention; and the scope ofprotection contemplated will be indicated in the appended claims.

In the accompanying drawings which are to be taken as a part of thisspecification, and in which I have shown merely a preferred form ofembodiment of the inven- Fig. 1 is a vertical sectional view through acentrifugal machine constructed in accordance withthis invention, partsbeing shown in elevation, and

Fig. 2 is a top plan view of the structureseen in Fig. 1. f

In the co-pending application referred td a device is shown in whichmeans is provided for braking the rotation of the rotatable element of acentrifugal machine co-incident with the cutting-off of driving power,and associated with means to lock the protecting and the driving powercut-off. It has been found in practice that additional means may beadvantageously used for preventing open-- ;ing movement of the coverduring the period of time while the brake is performing its cover closeduntil the brakeis thrown on .latch rod 16 is held, by the centrifugalforce function of stopping the rotating member.

The mechanism shown in the present application for applying a brakeco-incident with the cutting-ofi' of the driving power may be brieflydescribed as including a lever L to which is connected a switch blade 1for controlling the driving circuit of the motor- 2, the motor havinga-pulley 3 carried at the lower end of its shaft 4 and being connectedby belt 5 with the spindle 6 of the rotating element or basket G of themachine, and the basket being mounted within a casing H to which themotor 2 is connected. A brake lever 7 is connected with the lever L andwith a brake band 8 which surrounds a brake drum'9 provided upon thebasket G so that whenever the lever L is swungto break the drivingcircuit the brake band will be tightened for stopping the rotation ofthe basket.

The casing H has the usual hinged protecting cover 10 and the meansillustrated for preventing opening movement of this cover except whenthe brake is on comprises a link 11 connected with the cover and with aplunger 12 so that any opening movement of the cover is accompanied by asliding movement of the plunger in its supporting bearing 13.

Connected with the lever L is a second plunger 14 slidable in a path atright angles to the path of the plunger 12 and arranged to stand forobstructing movement of plunger 12 except when the lever L is in brakeapplying position, as more fully set forth in said co-pendingapplication.

Asa simple embodiment of means comprising the present improvement thedrawing illustrates the shaft 4 of the motor 2 as having connectedtherewith a centrifugally operated governor'devicev 15 with which isconnected a latch rod 16 projecting upwardly through an opening 17 ofthe bearing 13 and adapted for engaging within a notch 18 provided toreceive it in the plunger 12.

Whenever the motor shaft is rotating the of the governor device 15,pressed into the notch 18 so that theplunger 12 may notbe moved, and sothat the protecting cover 10 is thus held against being opened. Whenrotation of the motor shaft ceases however, and the centrifugal force ofthe governor device is thus removed, the latch rod will be pulled, or bedrawn, out of the notch 18 and leave the cover free to be lifted.

.It will be apparent from this disclosure that, owing to theco-operative relationship between the plungers 12 and 14, the cover mustnecessarily be closed before driving power can be applied to the rotor,and that the brake will at such time be released. The

notch 18 of the plunger 12 will thus of necessity be in position toreceive the latchv rod when the driving power is applied. As long as thedriving power remains applied the latch rod will continue in engagementwithin the notch. After the driving power is cutoff the latch rod willcontinue to stand in engagement with the notch until the basket and themotor shaft have lost their momentunli and have come practically to astand stil If for any reason the brake should fail to be effective whenthe driving power is cutoff the latch rod would nevertheless continue tohold the protecting cover 10 against possible opening movement until thebasket has ceased to rotate.

It will be understood that the motor 2, and the means for its control,is illustrated only in a conventional manner, and may be of any formdesired, either electrical, belt driven, or otherwise.

As many changes could be made in this construction without departingfrom the scope of the invention, as defined in the following claims, itis intended that all matter contained in the above description or, shownin the accompanying drawings shall be interpreted as illustrative onlyand not in a limiting sense.

Having thus described my invention, what I claim as new and desire tosecure by Letters Patent is 1. In a centrifugal machine, a rotatablemember, a drive motor connected to rotate said rotatable-member, adisplaceable guard for said rotatable member, a part connected with theguard to be moved thereby when the guard is displaced said part having ashoulder thereon, a bearing member within which saidpart is slidablymounted said bearing member having an auxiliary bearing openingtherethrough ext-ending laterally of the direction of movement of said'part, a device connected with the rotatable member to be rotated inconcert therewith, a latch rod movable in said auxiliary bearingopening, and connections between the latch rod and said device operableby the centrifugal power generated by rotation of said device to movethe latch rod within its auxiliary bearing intoengagement with saidshoulder forthereby preventing displacement of the gpard during rotationof the rotatable mem- 2. In a centrifugal machine, a rotatable basket, acarrier within which said basket is rotatably mounted, an electric motormounted upon said carrier, drive connections between the-motor and therotatable basket by which to rotate thebasket, a displaceable guardcarried by the carrier movable into and out of position for guarding thebasket, a bearing member carried by the carrier in a position above themotor, a part mounted in said bearing member slidable therein in ahorizontal direction and having'a shoulder thereon, con nections betweensaid part and the guard by which to slide said part when the guard isdisplaced, a device connected with the motor to be rotated therebywhenever the motor is in operation said bearing member having anauxiliary bearing therein opening downwardly toward the motor, a latchrod slidable in said auxiliary bearing and extending downwardlytherefrom toward the motor, and connections between the latch rod andsaid mentioned device operable by the centrifugal ower generated byrotation of said dev1ce or moving the latch rod upwardly through saidauxiliary bearing and into engagement with said shoulder for therebypreventing displacement of the guard during operation of the motor.

3. In a centrifugal machine, a rotatable basket, a carrier within whichsaid basket is rotatably mounted, an electric motor mountred upon saidcarrier, drive connections be ,the motor is in operation, said bearingmember having an auxiliary bearing therein opening downwardly toward themotor, a latch rod slidable in said auxiliary bearing and extendingdownwardly therefrom toward the motor, and connections between the latchrod and said mentioned device operable by the centrifugal powergenerated by rotation of said-device for moving the latch rod upwardlythrough said auxiliary bearing and into engagement with said shoulderfor thereby preventing displacement of the guard during operation of themotor, together with a brake for said basket, an operating handle forsaid brake, and means connected with said handle adapted to be movedthereby into and out of position controlling the sliding movements ofsaid mentioned part according as said brake is applied or released.

4. In a centrifugal machine, a rotatable member, a drive motor connectedto rotate said rotatable member, a displaceable guard for said rotatablemember, a part connected with the guard to be moved thereby when theguard is displaced said part having a shoulder thereon, a bearing memberWithin which said part is slidably mounted said bearing member having anauxiliary bearing opening therethrough extending laterally of thedirection of movement of said part, a latch rod movable in saidauxiliary bearing opening into and out of engagement with said shoulder,and means whereby the rotatable member will move the latch rod into andout of engagement with said shoulder according to Whether the rotatablemember is rotating or not, together with a brake for the rotatablemember, an operating handle for said brake, and means connected Withsaid handle adapted to be moved thereby into and out of positioncontrolling the sliding movement of said mentioned part according as thebrake is ap-. plied or released.

5. In a centrifugal machine, a rotatable member, a drive motor to rotatesaid rotatable member, a displaceable guard for said rotatable member, abrake for said rotatable member, a lock for said displaceable guard,means automatically operable by rotation of the rotatable member to holdthe displaceable guard against displacement during rotation of therotatable member, the combination therewith of a single manuallyoperable lover, and con- 1 nections between the lever the motor thebrake and the lock whereby operation of the motor the brake and the lockare directly controllable by movement of said single lever.

6. In a centrifugal machine, a rotatable member, a drive motor to rotatesaid rotatable member, a displaceable guard for said rotatable member, abrake for said rotatable memher, a lock for said displaceable guard,means automatically operable by rotation of the rotatable member to holdthe displaceable guard against displacement during rotation of therotatable member, the combination therewith of a single manuallyoperable lever, and connections between the lever the motor the brakeand the lock whereby manual movement of the lever in one direction willrelease the brake start the motor and lock the guard, While movement ofthe lever in an opposite direction will apply the brake stop the motorand unlock the guard.

In testimony whereof I aflix my signature.

HUBERT J. M. C. KRANTZ.

